I have recently replaced the tranny in a 1995 f150. It had broke and only reverse worked. I put one in that I had bought off a guy that said it worked perfectly. The truck starts and idles fine but about 80% of the time when you put it into reverse the engine quickly starts to die and you basically have to floor it to keep it running. Also it would shift extremely hard from 1st to 2nd or when downshifting from 2nd to 1st. So bad that now it stalls about 50% of the time if you do not keep you foot on the gas when stopping. I just assumed the tranny was bad so i replaced it with another one from a good running truck and it does the exact same thing.

Any help or suggestions would be greatly appreciated

Update: just tried changing the pcm and after about 2 mins of driving the problems started again.

 

did you replace your torque converter when you did that?

 

Yup i did.


Update: just pulled the codes and it returned "624"

 

624= EPC solenoid or driver circuit failure.

I don't know what that is, but it should be inside the tranny. Since you've installed two I'd have to say to check the wiring to the tranny for a broken wire or poor connection. Make sure your fuses are good too.

 

agreed. check all wiring. if thats good. that means its prolly the solonoid in the tranny. i tried replacing just one solonoid. but all the solonoids are together. and from the ford dealership it costs about $500 for that solonoid pack.
crazy i know.

 

if he got the exact same thing with 2 different trany then I would check the circuit...

this is controlled by the ECM so a bad ground or a pinched wire will do this...make sure the fender to engine ground is good as well as the engine to frame ground...and additional make sure the battery to fender post is clean and tight...I would actually pull them all and check them...